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1.
Nano Lett ; 23(18): 8753-8760, 2023 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-37712849

RESUMO

X-ray dose detection plays a critical role in various scientific fields, including chemistry, materials, and medicine. However, the current materials used for this purpose face challenges in both immediate and delayed radiation detections. Here, we present a visual X-ray dosimetry method for multienvironment applications, utilizing NaLuF4 nanocrystals (NCs) that undergo a color change from green to red upon X-ray irradiation. By adjustment of the concentrations of Ho3+, the emission color of the NCs can be tuned thanks to the cross-relaxation effects. Furthermore, X-ray irradiation induces generation of trapping centers in NaLuF4:Ho3+ NCs, endowing the generation of mechanoluminescence (ML) behavior upon mechanical stimulation after X-ray irradiation ceases. The ML intensity shows a linear correlation with the X-ray dose, facilitating the detection of delayed radiation. This breakthrough facilitates X-ray dose inspection in flaw detection, nuclear medicine, customs, and civil protection, thereby enhancing opportunities for radiation monitoring and control.

2.
Anal Chem ; 95(43): 15851-15855, 2023 10 31.
Artigo em Inglês | MEDLINE | ID: mdl-37857307

RESUMO

Identifying contaminants of specific bioactivities from complicated environmental matrices remains costly and time-consuming, as it requires us to not only resolve their structures but also determine their bioactivities. Herein, a novel noncovalent tagging method is integrated in mass spectrometry for identifying unknown contaminants that target dopamine (DA) receptors. Via proteolysis of bovine serum albumin, a stereoselective hexapeptide (ACFAVE) is selected for noncovalently tagging the contaminants that possess the stereostructural characteristics of binding to DA receptors. The tagged contaminants can be readily distinguished from the coexisting species for subsequent structural analysis based on the tagging-induced shifts of the mass-to-charge ratios. Thus, both bioactivity evaluation and structure analysis are accomplished via mass spectrometry. By using this method, 1,3-diphenylguanidine (DPG), a widely used additive in rubber and plastics, is successfully identified out of 2495 features detected in the Pearl River water, with its concentration determined as only 9.8 µg L-1. Furthermore, DPG is confirmed as a potential disrupter to the DA receptors via a simulated docking experiment, which has not been reported before. The present noncovalent tagging method provides a cost-effective and time-efficient way of identifying bioactive molecules in complicated matrices. And proteolysis of proteins is promising for developing more taggants with other desired stereoselectivities in the future.


Assuntos
Poluentes Químicos da Água , Água , Espectrometria de Massas , Água Doce , Plásticos , Soroalbumina Bovina , Poluentes Químicos da Água/análise
3.
Plant Cell Environ ; 46(12): 3887-3901, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37656830

RESUMO

Alfalfa (Medicago sativa L.) is considered to be the most important forage crop on a global scale. Nevertheless, soil salinity significantly decreases productivity, seriously threatening food security worldwide. One viable strategy is to explore salt stress-responsive factors and elucidate their underlying molecular mechanism, and utilize them in further alfalfa breeding. In the present study, we designated MsWRKY33 as a representative salt stress-responsive factor preferentially expressed in alfalfa roots and leaves. Subsequently, it was demonstrated that MsWRKY33 was localized in the cell nucleus, and functioned as a transcriptional activator of the W-box element. Transgenic alfalfa overexpressing MsWRKY33 displayed enhanced salt stress tolerance and antioxidant activities with no significant difference in other agronomic traits. Transcriptome profiling of MsWRKY33 transgenic alfalfa under control and salt treatment unveiled significantly altered expression of reactive oxygen species (ROS) scavenger genes in transgenic alfalfa. Subsequent examination revealed that MsWRKY33 binded to the promoter of MsERF5, activating its expression and consequently fine-tuning the ROS-scavenging enzyme activity. Furthermore, MsWRKY33 interacted with the functional fragment of MsCaMBP25, which participates in Ca2+ signaling transduction. Collectively, this research offers new insight into the molecular mechanism of alfalfa salt stress tolerance and highlights the potential utility of MsWRKY33 in alfalfa breeding.


Assuntos
Medicago sativa , Tolerância ao Sal , Medicago sativa/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Tolerância ao Sal/genética , Perfilação da Expressão Gênica , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Regulação da Expressão Gênica de Plantas
4.
Phys Chem Chem Phys ; 23(2): 1510-1519, 2021 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-33400744

RESUMO

The van der Waals heterostructure (vdWH) has attracted widespread attention as a unique structure for future electronic and optoelectronic devices. In this paper, we constructed the ZnO-SeMoS and ZnO-SMoSe vdWHs and systematically investigated their electronic structures and band alignments considering vertical strain and external electric field effects. It is found that the ZnO-SeMoS and ZnO-SMoSe vdWHs both exhibit type-II band alignment with indirect band gaps of 1.31 and 0.63 eV respectively, depending on the interface characteristics. What's more, the band alignment of these two heterostructures can be tuned to type I or type III, and their band gap can be modified to direct feature by applying vertical strain and an electric field. The results reveal that ZnO/MoSSe vdWHs have promising potential in multi-functional nanodevices, and provide a way to modify the electronic properties of Janus-based heterojunctions using interface characteristics.

5.
BMC Plant Biol ; 20(1): 226, 2020 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-32429844

RESUMO

BACKGROUND: α-Tocopherol is one of the most important vitamin E components present in plant. α-Tocopherol is a potent antioxidant, which can deactivate photoproduced reactive oxygen species (ROS) and prevent lipids from oxidation when plants suffer drought stress. γ-Tocopherol methyltransferase (γ-TMT) catalyzes the formation of α-tocopherol in the tocopherol biosynthetic pathway. Our previous studies showed that over-expression of γ-TMT gene can increase the accumulation of α-tocopherol in alfalfa (Medicago sativa). However, whether these transgenic plants confer increased drought tolerance and the underlying mechanism are still unknown. RESULTS: In the present study, we further evaluate transgenic alfalfa lines, and found that over-expression of MsTMT led to an increase in α-tocopherol and total tocopherol level in the transgenic lines compared with the control plant. It was revealed that drought tolerance of the transgenic alfalfa was remarkably increased, with alleviated oxidative damage and accumulation of more osmolytic substances. The stomatal development in transgenic plants was significantly inhibited on both sides of leaves, which may be resulted from the repression of MsSPCHLESS (MsSPCH) gene. The reduced stomatal density of transgenic plants contributes to a lower stomatal conductance and higher water use efficiency (WUE). Moreover, both RNA-seq and qRT-PCR analyses indicate that regulatory mechanism of MsTMT in drought involved in both ABA-dependent and ABA-independent pathways. CONCLUSION: Our results suggest that MsTMT gene plays a positive role in regulating alfalfa response to PEG-simulated drought stress, which might involve complex mechanisms, including ROS scavenging system, stomatal development and multiple phytohormone signaling pathways. This study will broaden our view on the function of γ-TMT gene and provide new strategy for genetic engineering in alfalfa breeding.


Assuntos
Secas , Regulação da Expressão Gênica , Medicago sativa/fisiologia , Metiltransferases/genética , Polietilenoglicóis/farmacologia , Vias Biossintéticas , Medicago sativa/enzimologia , Medicago sativa/genética , Metiltransferases/metabolismo , Plantas Geneticamente Modificadas/enzimologia , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/fisiologia , Vitamina E/metabolismo
6.
Small ; 16(7): e1907172, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31967725

RESUMO

Structural symmetry is a simple way to quantify the anisotropic properties of materials toward unique device applications including anisotropic transportation and polarization-sensitive photodetection. The enhancement of anisotropy can be achieved by artificial symmetry-reduction design. A core-shell SbI3 /Sb2 O3 nanowire, a heterostructure bonded by van der Waals forces, is introduced as an example of enhancing the performance of polarization-sensitive photodetectors via symmetry reduction. The structural, vibrational, and optical anisotropies of such core-shell nanostructures are systematically investigated. It is found that the anisotropic absorbance of a core-shell nanowire is obviously higher than that of two single compounds from both theoretical and experimental investigations. Anisotropic photocurrents of the polarization-sensitive photodetectors based on these core-shell SbI3 /Sb2 O3 van der Waals nanowires are measured ranging from ultraviolet (UV) to visible light (360-532 nm). Compared with other van der Waals 1D materials, low anisotropy ratio (Imax /Imin ) is measured based on SbI3 but a device based on this core-shell nanowire possesses a relatively high anisotropy ratio of ≈3.14 under 450 nm polarized light. This work shows that the low-symmetrical core-shell van der Waals heterostructure has large potential to be applied in wide range polarization-sensitive photodetectors.

7.
Artigo em Inglês | MEDLINE | ID: mdl-31913782

RESUMO

A stain of Pseudomonas sp. Lphe-2, which could degrade phenanthrene as the main carbon and energy source, was isolated from the aerobic sludge of a coking plant. Then its biodegradation characteristics, whole genome sequence and biodegradation pathway were examined. The Lphe-2 strain exhibited broad-spectrum degradation activities for various polycyclic aromatic hydrocarbons (PAHs), including naphthalene (NAP), phenanthrene (PHE), and pyrene (PYR). Under the optimal conditions, the degradation efficiency of phenanthrene (100 mg/L) is 92.76% on the 7th day, and 2-carboxybenzaldehyde and 1-hydroxy-2-naphthoic acid are the major metabolites found in phenanthrene metabolism. Genomic analysis of Pseudomonas sp. Lphe-2 showed that a total of 3879 genes from the Lphe-2 strain were annotated based on the COG classification, and the genomic information was annotated to 185 metabolic pathways. Based on the intermediate metabolites detected by Gas Chromatography-Mass Spectrometer (GC-MS) and all potential phenanthrene-degrading genes identified by BLAST search, a phenanthrene biodegradation pathway of Lphe-2 strain was proposed. These results suggested that Lphe-2 strain has a good prospect in the bioremediation of PAHs pollution.


Assuntos
Genes Bacterianos , Fenantrenos/análise , Pseudomonas/metabolismo , Esgotos/microbiologia , Poluentes do Solo/análise , Biodegradação Ambiental , Cromatografia Gasosa-Espectrometria de Massas , Genômica , Redes e Vias Metabólicas/genética , Anotação de Sequência Molecular , Naftalenos/análise , Naftalenos/metabolismo , Fenantrenos/metabolismo , Pseudomonas/genética , Pirenos/análise , Pirenos/metabolismo , Poluentes do Solo/metabolismo
8.
Microb Pathog ; 91: 41-5, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26657723

RESUMO

BACKGROUND: Acute diarrhoea is a common infectious disease among children in many countries and it has different kinds of clinical symptoms including vomiting, abdominal cramps, or fever of 38 °C. Some specific intestinal bacteria and their quantities can result in relevant symptoms. AIM: To analyze the correspondence between enteropathogenic bacteria and acute diarrhoea at family-level using high-throughput sequencing approach. METHODS: Every 30 children of acute diarrhoea with abdominal cramps, vomiting, and fever of 38 °C was regarded as a group, respectively. Stools samples were collected from each group and the DNA of stool was examined by E.Z.N.A.(®) Stool DNA Kit. The 16S rRNA genes sequencing was performed on an Illumina Miseq platform. FINDINGS: The sequencing dataset comprised 65,092 valid reads sequences that affiliated to the 18 phylogenetic families. The four dominant taxonomic groups in all three samples were Streptococcaceae, Veillonellaceae, Enterobacteriaceae and Lactobacillaceae. The stools of children with high fever presented higher pathogenic bacterial diversities and more complex community structures than other two groups. Lactobacillaceae was the enteric predominant microflora that could reduce the severity of acute diarrhoea. CONCLUSION: The reduction of predominant microflora or the aberrant proliferation of sub-dominant microflora can break the intestinal operation mechanism and cause intestinal diseases. What's more, people's living habits are also correlative about acute diarrhoea and parents should prepare light food for their children in order to protect their tender gastrointestinal mucosa.


Assuntos
Diarreia/microbiologia , Enterobacteriaceae/isolamento & purificação , Streptococcaceae/isolamento & purificação , Doença Aguda , Criança , China/epidemiologia , Diarreia/epidemiologia , Enterobacteriaceae/classificação , Enterobacteriaceae/genética , Enterobacteriaceae/crescimento & desenvolvimento , Fezes/microbiologia , Feminino , Humanos , Masculino , Filogenia , Streptococcaceae/classificação , Streptococcaceae/genética , Streptococcaceae/crescimento & desenvolvimento
9.
Biochem Biophys Res Commun ; 459(2): 208-213, 2015 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-25701792

RESUMO

Water channel proteins known as aquaporins (AQPs) regulate the movement of water and other small molecules across plant vacuolar and plasma membranes; they are associated with plant tolerance of biotic and abiotic stresses. In this study, a PIP type AQPs gene, designated as GoPIP1, was cloned from Galega orientalis, a high value leguminous forage crop. The GoPIP1 gene consists of an 870 bp open reading frame encoding a protein of 289 amino acids, and belongs to the PIP1 subgroup of the PIP subfamily. The transcript level of GoPIP1 was higher in the root of G. orientalis than in the leaf and stem. The level of GoPIP1 transcript increased significantly when treated with 200 mM NaCl or 20% polyethylene glycol (PEG) 6000. Transient expression of GoPIP1 in onion epidermal cells revealed that the GoPIP1 protein was localized to the plasma membrane. Over-expression of GoPIP1 increased the rosette/root ratio and increased sensitivity to drought in transgenic Arabidopsis plants. However, GoPIP1 over-expression in Arabidopsis had no significant effect under saline condition. The present data provides a gene resource that contributes to furthering our understanding of water channel protein and their application in plant stress tolerance.


Assuntos
Aquaporinas/genética , Aquaporinas/metabolismo , Galega/genética , Galega/metabolismo , Genes de Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Aclimatação/genética , Aclimatação/fisiologia , Sequência de Aminoácidos , Arabidopsis/genética , Arabidopsis/metabolismo , Clonagem Molecular , Desidratação , Secas , Regulação da Expressão Gênica de Plantas , Dados de Sequência Molecular , Filogenia , Plantas Geneticamente Modificadas , Salinidade , Homologia de Sequência de Aminoácidos , Estresse Fisiológico
10.
Sci Total Environ ; 912: 169129, 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38097077

RESUMO

Pyrethroid insecticides residues in water pose a critical threat to the environment from widespread production and overuse. Therefore, it is of major relevance to develop a sensitive and efficient method to detect pyrethroid insecticides in water. In this paper, a covalent organic framework (COF) with NHCO as the structural unit was synthesized using a simple condensation reaction of TTL (NH2) and TDBA (COOH). Various characterization results and density functional theory (DFT) calculations demonstrated that multiple interactions synergistically promoted the adsorption of pyrethroid insecticides on COFTDBA-TTL. Based on the excellent extraction capability of COFTDBA-TTL, efficient detection of 11 pyrethroid insecticides in water was achieved using COFTDBA-TTL-coated SPME fiber and gas chromatography-tandem mass spectrometry (GC-MS). The results showed that the extraction enhancement factors (EFs) of pyrethroid insecticides were as high as 2584-7199, and the extraction efficiencies were 3.28-446 times higher than that of commercial fiber, which reflected its high adsorption property. Meanwhile, the limits of detection (LODs) of the COFTDBA-TTL coated fiber were as low as 0.170-1.68 ng/L under the optimal conditions, and the recoveries of 11 pyrethroid insecticides in the actual water samples were 88.5-108 %. In conclusion, the SPME-GC-MS method based on COFTDBA-TTL coated fiber was simple, rapid, and efficient, and should have a promising application in trace detection of pyrethroid insecticides in the environment.

11.
Adv Mater ; 36(14): e2310617, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38207240

RESUMO

Tissue engineered bracket materials provide essential support for the physiological protection and therapeutics of patients. Unfortunately, the implantation process of such devices poses the risk of surgical complications and infection. In this study, an upconversion nanoparticles (UCNPs)-assisted 3D bioprinting approach is developed to realize in vivo molding that is free from invasive surgery. Reasonably designed UCNPs, which convert near-infrared (NIR) photons that penetrate skin tissues into blue-violet emission (300-500 nm), induce a monomer polymerization curing procedure in vivo. Using a fused deposition modeling coordination framework, a precisely predetermined trajectory of the NIR laser enables the manufacture of implantable medical devices with tailored shapes. A proof of the 3D bioprinting of a noninvasive fracture fixation scaffold is achieved successfully, thus demonstrating an entirely new method of in vivo molding for biomedical treatment.


Assuntos
Bioimpressão , Nanopartículas , Humanos , Luz , Próteses e Implantes
12.
Plant Commun ; 5(5): 100823, 2024 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-38243597

RESUMO

The inducible CRISPR activation (CRISPR-a) system offers unparalleled precision and versatility for regulating endogenous genes, making it highly sought after in plant research. In this study, we developed a chemically inducible CRISPR-a tool for plants called ER-Tag by combining the LexA-VP16-ER inducible system with the SunTag CRISPR-a system. We systematically compared different induction strategies and achieved high efficiency in target gene activation. We demonstrated that guide RNAs can be multiplexed and pooled for large-scale screening of effective morphogenic genes and gene pairs involved in plant regeneration. Further experiments showed that induced activation of these morphogenic genes can accelerate regeneration and improve regeneration efficiency in both eudicot and monocot plants, including alfalfa, woodland strawberry, and sheepgrass. Our study expands the CRISPR toolset in plants and provides a powerful new strategy for studying gene function when constitutive expression is not feasible or ideal.


Assuntos
Regeneração , Regeneração/genética , Sistemas CRISPR-Cas , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas/genética , Plantas Geneticamente Modificadas/genética , Regulação da Expressão Gênica de Plantas
13.
Biochem Pharmacol ; 224: 116230, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38643905

RESUMO

One of the effective therapeutic strategies to treat rheumatoid arthritis (RA)-related bone resorption is to target excessive activation of osteoclasts. We discovered that 6-O-angeloylplenolin (6-OAP), a pseudoguaianolide from Euphorbia thymifolia Linn widely used for the treatment of RA in traditional Chinese medicine, could inhibit RANKL-induced osteoclastogenesis and bone resorption in both RAW264.7 cells and BMMs from 1 µM and protect a collagen-induced arthritis (CIA) mouse model from bone destruction in vivo. The severity of arthritis and bone erosion observed in paw joints and the femurs of the CIA model were attenuated by 6-OAP administered at both dosages (1 or 5 mg/kg, i.g.). BMD, Tb.N and BV/TV were also improved by 6-OAP treatment. Histological analysis and TRAP staining of femurs further confirmed the protective effects of 6-OAP on bone erosion, which is mainly due to reduced osteoclasts. Molecular docking indicated that c-Src might be a target of 6-OAP and phosphorylation of c-Src was suppressed by 6-OAP treatment. CETSA and SPR assay further confirmed the potential interaction between 6-OAP and c-Src. Three signaling molecules downstream of c-Src that are vital to the differentiation and function of osteoclasts, NF-κB, c-Fos and NFATc1, were also suppressed by 6-OAP in vitro. In summary, the results demonstrated that the function of c-Src was disrupted by 6-OAP, which led to the suppression of downstream signaling vital to osteoclast differentiation and function. In conclusion, 6-OAP has the potential to be further developed for the treatment of RA-related bone erosion.


Assuntos
Artrite Experimental , Reabsorção Óssea , NF-kappa B , Fatores de Transcrição NFATC , Osteoclastos , Osteogênese , Animais , Camundongos , Fatores de Transcrição NFATC/metabolismo , Células RAW 264.7 , Reabsorção Óssea/tratamento farmacológico , Reabsorção Óssea/metabolismo , Reabsorção Óssea/prevenção & controle , Artrite Experimental/tratamento farmacológico , Artrite Experimental/patologia , Artrite Experimental/metabolismo , Artrite Experimental/induzido quimicamente , Osteogênese/efeitos dos fármacos , NF-kappa B/metabolismo , Osteoclastos/efeitos dos fármacos , Osteoclastos/metabolismo , Masculino , Transdução de Sinais/efeitos dos fármacos , Proteína Tirosina Quinase CSK/metabolismo , Simulação de Acoplamento Molecular , Quinases da Família src/metabolismo , Quinases da Família src/antagonistas & inibidores
14.
Nanoscale Adv ; 4(14): 3023-3032, 2022 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-36133511

RESUMO

We systematically investigate the transport properties of monolayer arsenene tunneling field-effect transistors (TFETs) along the armchair and zigzag directions using first-principles calculations based on density functional theory (DFT) combined with the non-equilibrium Green's function (NEGF) approach. We introduce five types of defects at the source-channel interface and study their influences on the device performance. The pristine arsenene TFETs along the armchair direction have large ON-state currents due to the small effective masses, but still cannot meet the International Technology Roadmaps of Semiconductor 2022 (ITRS 2022) requirements for high performance (HP) devices. The adsorption of one and two H atoms can significantly enhance the ON-state currents to above 1412 µA µm-1 and reduce subthreshold swing (SS) to below 60 mV decade-1 for both n- and p-type devices, satisfying the ITRS 2022 requirements for HP devices. Besides, the p-type As and the n-type Li adatoms can improve the performance of p-type and n-type devices, respectively. The pristine arsenene TFETs along the zigzag direction with low ON-state currents already meet the ITRS 2022 requirements for low-power (LP) devices. The performance of the p-type TFETs as LP devices can be improved by p-type SV and the As adatom by increasing the ON-state currents and/or reducing the SS. On the other hand, the adsorption of one H adatom can remarkably increase the ON-state current of the p-type TFET to 1563 µA µm-1 and reduce SS to 34 mV decade-1, allowing the device to work as an HP device. We further confirm that the enhancement of the ON-state currents is due to the shortening of the band-to-band tunneling path through the defect induced gap states. Our calculations provide a theoretical guide to improve the performance of TFETs based on arsenene or other monolayer materials by suitable defects.

15.
Plants (Basel) ; 11(7)2022 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-35406919

RESUMO

Branching is one of the key determinants of plant architecture that dramatically affects crop yield. As alfalfa is the most important forage crop, understanding the genetic basis of branching in this plant can facilitate breeding for a high biomass yield. In this study, we characterized the strigolactone receptor gene MsD14 in alfalfa and demonstrated that MsD14 was predominantly expressed in flowers, roots, and seedpods. Furthermore, we found that MsD14 expression could significantly respond to strigolactone in alfalfa seedlings, and its protein was located in the nucleus, cytoplasm, and cytomembrane. Most importantly, transformation assays demonstrated that silencing of MsD14 in alfalfa resulted in increased shoot branching and forage biomass. Significantly, MsD14 could physically interact with AtMAX2 and MsMAX2 in the presence of strigolactone, suggesting a similarity between MsD14 and AtD14. Together, our results revealed the conserved D14-MAX2 module in alfalfa branching regulation and provided candidate genes for alfalfa high-yield molecular breeding.

16.
ACS Appl Mater Interfaces ; 13(29): 34178-34187, 2021 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-34258989

RESUMO

Two-dimensional (2D) materials with excellent photocatalytic properties and unique piezoelectric response have attracted great attention. However, these characters are rare for traditional 2D structures. With an intrinsic electric field, the Janus 2D materials show great promise in photocatalytic and out-of-plane piezoelectric applications. Herein, we show that Janus In2X2X' (X and X' = S, Se, and Te) monolayers are desirable in the overall water splitting and piezoelectric devices. Comprehensive investigations reveal that the band gaps of these Janus monolayers are from 0.34 to 2.27 eV. With proper band edge positions, strong solar absorption, fast transfer and efficient separation of carriers, and high solar to hydrogen (STH) efficiencies (reaching 37.70%), eight members of them stand out. Besides, the electrons and holes have sufficient driving forces in the process of redox reaction. The piezoelectric response for in- and out-of-plane is superior for all monolayers. These compelling features make them suitable for photocatalysts, sensors, actuators, and energy conversion devices.

17.
Front Plant Sci ; 12: 775690, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35069631

RESUMO

SQUAMOSA Promoter-binding protein-Like (SPL) genes affect a broad range of plant biological processes and show potential application in crop improvement by genetic modification. As the most widely planted forage crop in the world, biomass and abiotic stresses tolerance are important breeding targets for alfalfa (Medicago sativa L.). Nevertheless, the systematic analysis of SPL genes in alfalfa genome remains lacking. In the present study, we characterized 22 putative non-redundant SPL genes in alfalfa genome and uncovered the abundant structural variation among MsSPL genes. The phylogenetic analysis of plant SPL proteins separated them into 10 clades and clade J was an alfalfa-specific clade, suggesting SPL genes in alfalfa might have experienced gene duplication and functional differentiation within the genome. Meanwhile, 11 MsSPL genes with perfect matches to miRNA response elements (MREs) could be degraded by miR156, and the cleavage sites were gene specific. In addition, we investigated the temporal and spatial expression patterns of MsSPL genes and their expression patterns in response to multiple treatments, characterizing candidate SPL genes in alfalfa development and abiotic stress tolerant regulation. More importantly, overexpression of the alfalfa-specific SPL gene (MsSPL20) showed stable delayed flowering time, as well as increased biomass. Further studies indicated that MsSPL20 delayed flowering time by regulating the expression of genes involved in floret development, including HD3A, FTIP1, TEM1, and HST1. Together, our findings provide valuable information for future research and utilization of SPL genes in alfalfa and elucidate a possibly alfalfa-specific flowering time regulation, thereby supplying candidate genes for alfalfa molecular-assisted breeding.

18.
Guang Pu Xue Yu Guang Pu Fen Xi ; 30(4): 883-6, 2010 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-20545123

RESUMO

The rise and decay curves of Er3+ 4F9/2 upconversion emission in oxyfluoride tellurite glass were measured under the excitation at 808 nm from a laser diode driven by square waves. The lifetime of the intermediate state could be determined via rise times. Then the accumulation process of the 4F9/2 population was confirmed. The excitation mechanism of up-conversion red emission under 808 nm excitation was confirmed by the rate equations and analyzing the relationship between the time constants of the rise and decay processes and the intermediate state. Square wave excited upconversion emission may also be used for measuring lifetimes of infrared energy levels with a conventional photomultiplier tube.

19.
Biotechnol Biofuels ; 13: 162, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32973923

RESUMO

BACKGROUND: Extracellular electron transfer (EET) is essential in improving the power generation performance of electrochemically active bacteria (EAB) in microbial fuel cells (MFCs). Currently, the EET mechanisms of dissimilatory metal-reducing (DMR) model bacteria Shewanella oneidensis and Geobacter sulfurreducens have been thoroughly studied. Klebsiella has also been proved to be an EAB capable of EET, but the EET mechanism has not been perfected. This study investigated the effects of biofilm transfer and electron mediators transfer on Klebsiella quasipneumoniae sp. 203 electricity generation performance in MFCs. RESULTS: Herein, we covered the anode of MFC with a layer of microfiltration membrane to block the effect of the biofilm mechanism, and then explore the EET of the electron mediator mechanism of K. quasipneumoniae sp. 203 and electricity generation performance. In the absence of short-range electron transfer, we found that K. quasipneumoniae sp. 203 can still produce a certain power generation performance, and coated-MFC reached 40.26 mW/m2 at a current density of 770.9 mA/m2, whereas the uncoated-MFC reached 90.69 mW/m2 at a current density of 1224.49 mA/m2. The difference in the electricity generation performance between coated-MFC and uncoated-MFC was probably due to the microfiltration membrane covered in anode, which inhibited the growth of EAB on the anode. Therefore, we speculated that K. quasipneumoniae sp. 203 can also perform EET through the biofilm mechanism. The protein content, the integrity of biofilm and the biofilm activity all proved that the difference in the electricity generation performance between coated-MFC and uncoated-MFC was due to the extremely little biomass of the anode biofilm. To further verify the effect of electron mediators on electricity generation performance of MFCs, 10 µM 2,6-DTBBQ, 2,6-DTBHQ and DHNA were added to coated-MFC and uncoated-MFC. Combining the time-voltage curve and CV curve, we found that 2,6-DTBBQ and 2,6-DTBHQ had high electrocatalytic activity toward the redox reaction of K. quasipneumoniae sp. 203-inoculated MFCs. It was also speculated that K. quasipneumoniae sp. 203 produced 2,6-DTBHQ and 2,6-DTBBQ. CONCLUSIONS: To the best of our knowledge, the three modes of EET did not exist separately. K. quasipneumoniae sp.203 will adopt the corresponding electron transfer mode or multiple ways to realize EET according to the living environment to improve electricity generation performance.

20.
Psychiatry Res ; 290: 112963, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32450410

RESUMO

To evaluate the relationships between problematic Internet use (PIU) and suicidal ideation (SI) among adolescents, we encompassed 12,507 participants (16.6 ± 0.8 years). The occurrence of mood disorders, quality of life (QOL), personality traits and SI were compared in adolescents with and without PIU. Multilevel logistic regression models, trend analysis and interaction analysis were employed. A total of 2,809 (22.46%) adolescents reported SI. PIU was assessed using Internet Addiction Test score (IATs), and 3,442 (27.52%) participants met the criteria for PIU (IATs ≥ 40). PIU was significantly and independently associated with SI [AOR for suicidal ideation (vs. IATs < 40): 1.00 for 40-59 points; 1.3 (CI, 1.2-1.5): 60-79 points; 1.7 (CI, 1.4-2.1): 80-100 points; and 2.2 (CI, 1.2-3.9)]. Trend analysis demonstrated that PIU increased the risk of SI in each of the subgroups (p for trend ≤ 0.001 for each). Interaction analysis showed an association of PIU and SI that were dependent on mood disorders, QOL, impulsivity and aggression (p-value for interaction < 0.05). These findings highlight the need for a range of cross disciplinary health interventions to afflicted families, students, and clinicians, to increase the awareness of adverse PIU effects.


Assuntos
Comportamento do Adolescente/psicologia , Povo Asiático/psicologia , Transtorno de Adição à Internet/psicologia , Internet/estatística & dados numéricos , Qualidade de Vida/psicologia , Estudantes/psicologia , Ideação Suicida , Adolescente , Comportamento do Adolescente/etnologia , Agressão , Povo Asiático/estatística & dados numéricos , Estudos Transversais , Feminino , Humanos , Comportamento Impulsivo , Transtorno de Adição à Internet/etnologia , Masculino , Adulto Jovem
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